Pneumonia is an infection of the lungs. It is a serious illness that can affect people of any age, although it is most serious in the very young, people over the age of 65, and those with certain underlying medical problems. It is most common during the winter months.
The mouth and respiratory tract are constantly exposed to microorganisms as air is inhaled through the nose and mouth. However, the body’s defenses are usually able to prevent microorganisms from entering and infecting the lungs. These defenses include the immune system, the specialised shape of the nose and pharynx, the ability to cough, and fine hair-like structures called cilia located on the bronchi which aid in expulsion of these potential disease causing organisms. Pneumonia can develop if one of these defences isn’t adequate or the microorganism is particularly strong.
As microorganisms multiply, the alveoli become inflamed and accumulate fluid. These changes lead to the symptoms of pneumonia.
Some groups of adults are at a greater risk of developing pneumonia. These include; people older than 65 years, cigarette smokers, malnourished due to health conditions or lack of access to food. Some people with underlying lung diseases such as cystic fibrosis, asthma, or chronic obstructive pulmonary disease have an increased risk of developing pneumonia. People with other underlying medical problems, including diabetes or heart disease, a weakened immune system due to HIV, organ transplant, chemotherapy, or chronic steroid use, also increases chances of suffering from pneumonia. Other people with difficulty coughing due to stroke, sedating drugs or alcohol, or limited mobility and those who had a recent viral upper respiratory tract infection including influenza.
Pneumonia can be caused by a variety of microorganisms including viruses, bacteria, and less commonly, fungus. Fungus rarely cause pneumonia in people who are generally healthy; people with a weakened immune system (those with HIV, organ transplant patients, or those on chemotherapy) are at higher risk of fungal infection.
Pneumonia is usually diagnosed with a medical history and physical examination, as well as a chest x-ray. The need for further testing depends on the severity of the illness and the person’s risk of complications.
Sputum testing requires a sample of sputum, collected from a deep cough. Culture of sputum is used to identify the bacteria that caused the pneumonia and can help determine which antibiotic is best.
Blood tests can be done to look out for any features of bacterial infection.
Once the diagnosis of pneumonia has been made, the goal of treatment for patients is to treat the infection and prevent complications. Initial treatment of pneumonia is based on the organism that is likely to be causing pneumonia (called empiric treatment). Most patients improve with empiric treatment.
Most patients are treated for pneumonia at home with oral antibiotics. People who are seriously ill or are at increased risk for complications may be hospitalised. The number of days spent in the hospital is variable, and depends on how a person responds to treatment and if there are underlying medical problems.
A number of antibiotic treatment regimens exist for treatment of community acquired pneumonia. The choice of which antibiotic to use is based on several factors, including the person’s underlying medical problems and the likelihood of being infected with bacteria that is resistant to specific drugs.
Pneumonia is usually treated successfully without developing complications. However, complications can develop in some patients, especially those in high-risk groups. These might include; fluid accumulation in chest, formation of pus in the chest, generalised infection and sometimes, death.
The pneumococcal vaccine is one of the most effective ways to prevent pneumonia. The influenza (or “flu”) vaccine is important not only for preventing influenza but also for preventing its complications, including pneumonia.
Infection control measures can help to prevent the spread of any type of infection, including pneumonia. Infection control is most commonly practiced in healthcare settings, but is useful in the community as well. Simple practices such as frequent hand washing with soap and water or alcohol-based hand rubs can be effective.
Dr. Ian Shyaka ,
Resident in Surgery, Rwanda Military Hospital,